Yellow disazo dyestuff for wool.



ca rn-n srairas PATNT t me.

AUGUST LEOPOLD LASKA, 0F OFFENBACH-0N-TI-IE-MAIN; GERMANY, ASSTGNOR TOTHE CORPORATION OF CHEMISCHE FABRIK GRIESHEIM ELEKTBON, FRANK-FORT-ON-THE-MAIN, GERMANY.

YELLOW DISAZO DYESTUFF FOR WOOL.

N 0 Drawing.

Specification of Letters Patent.

'App1icati0n filed May 5, 1910. Serial No. 559.540.

Patented Get. 4,, 19M).

wherein X means CH or Cl, with two molecules 1 sulfoaryl 3 methyl 5pyrazolone. The thus obtained dyestuffs dye wool from acid bath yellowshades fast without aftertreatment with chromates to white wool andcotton in the milling process. Diamins of the aforesaid constitution aremeta-tolidin and meta-meta-dichlorobenzidin.

The following examples will serve to illustrate the nature of myinvention and how it can be carried out; parts being by weight.

Example I: 10.6 parts of meta-tolidin are tctrazotized and combined withan ice cold solution of 25.5 parts of 1-para-sulfophenyl-3-methyl-5-pyrazolone. The solution is kept alkaline by addition of sodatill the formation of dyestufi is complete. The temperature of themixture isthen raised to 70 and the dyestufi' precipitated by additionof common salt. The dyestuff forms a yellow brown owder, dissolving inconcentrated sulfuric acid with reddish-yellow, in water with. yellowcolor; the aqueous solution is scarcely altered by addition of causticsoda lye; by addition of hydrochloric acid the dyestufi" is precipitatedin form of yellow flakes. It dyes wool yellow shades fast againstmilling.

Example II: 12.65 parts of meta-dichlorobenzidin are tetrazotized andcombined with an ice cold solution of 25.5 parts of l-parasulfophenl-3-methyl-5-pyrazolone. The solution is lzept alkaline by addition ofsoda till the formation of dyestuff is complete.

The temperature of the mixture is raised to 70 and the dyestuffprecipitated by addition of common salt. The dyestulf forms ayellow-brown powder and dissolves in concentrated sulfuric-acid withreddish-yellow, in. water with yellow color. This solution is scarcelyaltered by addition of caustic soda lye; by addition of hydrochloricacid the dyestuft' is precipitated in form of yellow flakes. It dyeswool yellow shades fast against milling.

Tn analogous manner the formation of dyestufl' may be performed by usingother sulfoarylmethylpyrazolones, isomerics, homologues, or chlorinsubstitution products of 1 para sulfophenyl 3-methyl-5-pyrazolone, forinstance 1-me'ta-sulfophenyl-3- methyl 5 pyrazolone, 1 parasulfo-orthotolyl-3-methyl-5 pyrazolone, l-ortho-chloroparasulfophenyl-3-methyl-5-pyrazol0ne, 1- ortho chlorometa-sulfophenyl-3-methyl-5- pyrazolone, 1-para chloro-meta-sulfophenyl-3-methyl-5-pyrazolone,1-4-sulf0-2z5-dichlorophenyl-3-methyl-5-pyrazolone.

All these dyestuffs show the same substantial properties, 2'. 6. theydye wool yellow shades varying from greenish-yellow to reddish-yellowaccording to the constitution of the aryl radical, and are-fast to whitewool and cotton in the milling process. They may also be used withadvantage for production of pigment colors.

Now what I claim and desire to secure by Letters Patent is thefollowing:

1. The process for the manufacture of yellow disazo dyestuffs-for woolconsisting in combining the te'trazo compounds of diamins of the generalformula:

wherein X means CH or G1, with two molecules of1-sulfophenyl-3-methyl-5-pywherein X may be CH or G1, with two moleculesof 1-sulfoaryl-3-methyl-5-pyrazolone, said dyestuffs being yellow-brownpowders, dissolving in concentrated sulfuric acid with reddish-yellow,in water with yellow color, the aqueous solution being scarcely alteredby addition of caustic soda lye, the dyestufi being precipitated in formof yellow flakes by addition of hydrochloric acid, the said dyestufisdyeing wool yellow shades fast against milling.

3. The process for the manufacture of yellow disazo dyestufis for woolconsisting in combining the tetrazo compound ofmetameta-dichlorobenzidin with two molecular proportions of 1 sulf-oaryl3 methyl-5-pyrazolone.

4. As new articles the dyestuffs obtained by combining the tetrazocompound of metameta-dichlorobenzidin with two molecular proportions cl1 sulfoaryl 3 methyl-5-pyrazolone being yellow-brown powders,dissolvingin concentrated sulfuric acid with reddish-yellow, in waterwith yellow color, which solution is scarcely altered by addition ofcaustic soda dye, the dyestuff being precipitated by addition ofhydrochloric acid; the said dyestuffs dyeing wool yellow shades fastagainst milling.

In testimony, that I claim the foregoing as my invention, I have signedmy name in presence of two witnesses, this 22nd day of April 1910.

AUGUST LEOPOLD LASKA. .Vitnesses:

EVA SATI'LER, OSKAR STANDHARDT.

